Hydraulic turbine



Sept. 4, 192s.

L. F. MOODY HYDRAULIC TURBINE Original Filed June 25, 1924 Patented Sept. 4, 1928 LEWIS FERRY MOODY, F PHILADELPHIA, PENNSYLVANIA.

HYDRAULIC TURBINE.

Original application vled June 25, 1924, Serial No. 722,228. `Divided and this application led l November`24, 1925. Serial No. 71,074.

This invention relates to hydraulic turbines and particularly to turbines of relatively high specific speed.

One object of the invention is to provide such a turbine in which the construction and operation will be simplified and cheapened by dispensing with the usual wicket gates and replacing them by a simple, sliding cylinder gate to control'the flow with a transition space intervening between the o'ate and the entrance edges -of the runner blades in order to insure steady, smooth and efficient action of the runner.

Another object of the invention is to prov-ide a special, compound form of runner particularly adapted to cooperate with such a means of control. This case is a divisionof my copending application', Serial No. 722,228, ledJ une 25,1924.U v.

A further object of the invention is to provide means for admitting air to the region behind the gate when in intermediate -position.

In the accompanying drawings illustrating the invention ,l b

Fig. 1' is a vertical sectional view of the turbine showing a means of actuating the gate by fluid pressure;

Fig. 2 is a plan view of the runner.

Inv the embodiment ofthe invention' shown in Fig. 1 water enters from the casing 10 and passes through the guide vanes 11 which give 1t a combined radial and tangential motion with respect to the turbine axis. It then mately axial direction and directs the water against a high-speed, peripherally unshroud- ,ed, propeller-type runner 13. The water is disc arged from the runner in adirection chiefly axial and with tangential'components of reduced amountl and enters the draft tube 14,' which is preferably of theannular form shown, comprising the outer wall 15 and inner core 16. The runner 13 contains the hub 17 keyed to the vertical shaft 18 which is lat- -erally' supported by the guide bearin @he bewng 19 passes through the transition space 12 whichl turns the radial components into an approxi.

, ,9 is varied. within @halladcover 20 which is connected by the flange 21 with the pit liner 25 extending upward from 50` the speed ring having vanes 1l.

A caslng 51 surrounds the runner blades and forms the base for the stay vanes 11 and i liner 25. The casting 51 containsa removable seat may be separate where desired. When `turbines of the propeller t e are applied to fairly high heads, such aylpiner is advanta-l geous in case corrosion develops in the casin surrounding the runner due to eddies forme adjacent to the runner blades,` and the liner will have a further advantage'obeing renewable case foreign materialbecoines lodged in. the clearance space outside the runnerl blades and Ascores the surface of the wall.

The cylinder gate 26 slides between the up- 75 per distributor ring 23 and the head cover 20 and is actuated by the piston flange 27 sliding withinthe pit liner 25 which, with the head cover 20, forms fan \annular` cylinder. Fluid pressure may be admitted or exhausted under control of the turbine governor through .pipes 28 and 29 to .lower or raise the c linderv gate"26 and thus to regulate the il w t rough the turbine and thereby to control its load and speed.

With the cylinder gate 2fin'full7 1 opened position, the flow entering through t e intake -10 and combined guide and 4stay vanes 11 passes with combined radial and tangential components into the transition space 12 where n it is turned downward toward the axial direction and on to the runner 13. In this transition space the streams from the passages between the vane's 11 are gathered together into 'a continuous rotating mass before bein di- 9s raced agees? the runner. at manne la@ positions of the cylinder 'gate 26, the upper, inner portion of the flow will be ,partially cut oi so that at partgate the flow will be delivered mainly at the outer ends of the runner blades.

When desired, air may be admitted to the inner portion of the transition space 12 so that the annular stream entering the transition space at partgate positions of the cylinder ate 26 will have an inner free surface withln which the space 12 is free from the iiow by the admission of air. The space be-l hind the cylinder gate which would otherwise be occupied by water in a more or less eddying and turbulent condition will be rey placed by air, and the loss of energy in such eddies will be reduced or avoided. At the same time the internal circulation Within the runner occurring at partgate inyolving an upward fiow near the hub and a return flow .j through the outer portions of the blades will be reduced. The air admitted through the pipe 30 which may be fitted with suitable valve or control means passes through, the ports 31 into the transition space. The c linder gate 26 is advantageous in being su ject to but little hydraulic load and requiring little power to operate it, the governor power being required chiefly to overcome the friction of the gate. The gate mechanism is, in the arrangement shown, reduced to a single movingpart of rugged construction and simple arrangement. This form of turbine is therefore simple and durable and relatively inexpensive, and is particularly suited to installations of small or moderate size under low or moderate heads. The transition space and runner areof such form and so arranged with relation tothe cylinder gate that therunner blades -do not.

pass immediately through the region of turbulence behind the gate when in partgate position. Suilicient space is provided for the water to form a smoothly owing, continuous body of water by the time it encounters the runner blades with but little turbulence then remaining, thus avoiding unsteadiness of operation of the runner or corrosive effects on the runner blades.

I turbine of this form is well adapted to installations operating under relatively steady loads and where very high partgate efficiency is not important. An enclosed intake passage or casing 10 may be used as shown, this casing being preferably of volute form, or when desired, the turbine can be arranged for an open flume setting.

The runner 13 is of a special compound type comprising two concentric series of vanes or blades including an outer series 58 and an inner one 59, the two series being separated by an intermediate ring or partition inner series 59 within the partition 42. In this case four blades or vanes 59 are used in the inner series, this number being suiicient to provide proper guidance for the flow through the central ortion of the runner, and six unshrouded o ades 58 are used in the outer series where the circumferential distance around the runnei` is greater. Thus the partition ring connects the vanes to ether at an intermediate point bet-Ween the ub and the tips. This ring thus carries on its exterior the series of unshrouded blades 58 having no further connection atl their tips. This partition increases the mechanical strength of the runner byinterconnecting all of the blades and is placed at such a radial position between the tips and hub that it provides both maximum mechanical strength and at the same time has a'lower linear velocity throu h the water than it would have if place at the outer tips of'the blades. This reduced linear velocity correspondingly reduces the hydraulic surface losses due to the dragging of thefring through the water, since the water ilicontact with this ring nas a lower relative velocity against the ring than would occur if the ring were located vat the blade tips. The ring is also advantageous under partgate conditions of operation, for when the gate is in such position, the ring or partition will serve to guide the flow and to 'reduce the wasteful internal circulation of water within the runner.

The compound form runner furnishes a useful construction for the intermediateJ range of specific speeds between the high speed Francis or mixed-flow form of runner having an outer band or shroud ring and the unshrouded propeller 'type runners of still higher specific speed On account of I the added strength furnished by the partition ring, the inner series of blades can be made thinner or shorter or fewer in number than would be necessary in a simple unshrouded runner, and this can be accomplished without incurring the hydraulic losses due to an outer band or shroud. This compound form of runner is capable of securing increased partgate efficiencies as well as high maximum efficiencies in runners of moderately high specific speeds. In either or both series of blades an axial opening may be provided between the blade edwcs as shown by Fig. 2. That is, it the area oi? each blade of a series is projected on to a plane normal to the runner axis it would, if superimposed on the area of the annular opening between the partition ring and curb ring, or between the hub and partition ring, projected on to said plane, leave a portion of said' latter area uncovered.

This application is a division of my original application Serial Number 722,228, tiled f 42 conforming torthe flow lines through the \J une 25, 1924.

runner. The o'uter series of blades58 contains a different number vof blades from the' I claim:- 1. In combination with a hydraulic turbine having an intake and discharge, of a on to a plane normal to the runner the annular having an intake and discharge, ofa propeller-type runner comprising an inner series of vanes, a partition ring connecting the ends of said vanes, and an outer series of unf shrouded vanes extending outwardly from said partition ring, the outer portion of said unshrouded vanes being more nearly shrouded vanes extending `outwardly from,

said partition ring, the outer portion of said unshrouded vanesbeing more nearly horizontal than vertical and one of said series having a greater number of 4vanes than the gother.

i 3. In combination with a hydraulic turbine having an intake and discharge, of a runner having two concentric annular water pas-V sages, each passage containing a series of a relatively small number of vanes, the inner and outer series having projected areas in a plane normal to the runner axis which are less than the areas of their respective. annular passages projected in the same plane.

4. .In combination with a' hydraulic turbine having an intake and discharge, of a runner comprising inner and outer series of vanes, the adjacent edges of each series voi'vanes being spaced to provideaxial openings.

5. In combination with a hydraulic turbine having an intake anddischarge, of a runner having a series of avrelatively small number of vanes and a shroud ring connecting the ends thereof, the area of said vanes projected axis being less thanV the projected area of passage within said shroud ring:J

6. In combnationwith a hydraulic turbine having an intake and discharge, of a runner having an annular water passage containing a'series of vanes, a shroud ring connecting the ends of said vanes, and the adjacent edges of said vanes being spaced to form an axial opening through said annular passage.

7 In combination with ahydraulic turbi `e er having a series of vanes, the ends of which are connected by a shroud ring, the projected area of said vanes on to a plane normallto the runner axis beingv less than the area of the within vsaid shroud ringkthe annular passage lower edge of said ring extending to the lower edge of each vane. Y'

8. In vcombination with a hydraulic turbine having an intake and discharge, of a runner )having an annular water passage containing a. sefies of vanes, and a. shroud ring'connecting the ends of said vaines,- the adjacent edges of said vanes being spaced to forman axial opening through said annular passage, the upper edge of said shroud ring terminating adjacent the up r edge of said vanes.

9. In combina ion with a hydraulic turbine having an intake and discharge, of a runner having anannular water passage containing a series of vanes, and a shroud ring connecting the ends ofsaid vanes, the-adjacent edges of said vanes being spaced to form an axial o enino throiirh saidannular assa e, the

P is e P g upper and lower edges of said shroud ring terminating adjacent the upper and lower edges of lsaid vanes."

l0. In combination with a hydraulic turbine having .an intake anddischarge, of a runner of the propeller' type having an annular passage with a series of vanes therein, a shroud ring connecting said vanes, and an outer series of vane extending outwardly ufrom'said shroud ring; and having a different `number of vanes 'from that in said' other series, the upper and lower edges org said ring terminating adjacent'the upper and lower` edges of said vanes.

11. In combination with a hydraulic turbine having an intake and discharge, of a. runner vof the propeller type having analinular passage and a series of vanes disposed therein, a shroud ring'co-nnecting said vanes,

-and an outer series of vanes extending outwardly from said shroud ring and having a different number of vanes from that in said other series, said ring being provided Witli an approximately straight outer surface in meridian section. i

12. In combination with a hydraulic turbine having an'intake and discharge, of a runner of the propeller type having an annular passage and a series of vanes di osed therein, a shroud ring connecting the ends of said vanes, and an outer series of vanes of greater number than said other series the up: per and lower edges of saidring terminating adjacent the upper and lower edges of said -vanes and said ring being inclined to the runner axis. Y

13. In combination with a hydraulic turbine having an intake and discharge, of a Jrunner of the propeller type havingan annular passage and a' series of vanes disposed ling adjacent the upper and lower edges of 'l said vanes, said ring having a curved inner surface. A

14. In combination with a hydraulic ti1r bine having an intake and discharge, ofa,-

runner 'of the propeller type having an annular passage and a series of veins disposed.I

therein, a shroud ring connecting the ends of s'aidvanes, and an outer series of vanes of greater number than said other series the upper and lower'edges of said ring terminaitl ing adjacent the up r and lower edges of said vanes, said ringlbeeing provided with an approximately straight outer surface in meridian section.

15. In combination with a hydraulic tur- 'bine having an intake and discharge, of a tween said series, the outer series being more 'horizontal than vertical at the blade tips, supported entirely by .saidring, and certain of the' inner vanes being offset from the outer' vanes. v17. In combination with a'propeller type hydraulic turbine having an intake and discharge, of a runner comprising an inner and outer series of vanes, said outer vanes being more'horizontal than vertical at the blade tips, a partition ring for separating said series, certain of the inner vanes being oset from the outer vaneswhile certain other Lof the inner vanes are substantially in alignment with certain of the outer vanes.

18. Inca hydraulic turbine, the combination with a runner having an inner and outer series of vanes, certain of the vanes in each series being spaced to provide axial spaces therebetween, and a partition ring for separating said series, of an intake for the flow to said runner, and means for forming a transi- 'tion space between said intake and runner.

19. In a hydraulicl turbine, the combination with a propeller type runner having an inner and outer series 'of vanes, said outer series ofvanes being more horizontal than vertical at the blade tips, a partition ring separating said series one of which has a greater number of vanesv than the other, of an intake for the iow to said runner, and means for directing an axial iiow from said intake to said runner.

20. In a hydraulic turbine, the combination with a propeller type runner having an inner and outer series of vanes, said outer series of vanes bein more horizontal than vertical at the blade tips, a partition ring separating said series one of which has a greater number of vanes than the other, of an intake for the iiow to said runner, and stay vanes between said intake and runner, thereby to impart a whirling motion to the turbine flow.

21. In a hydraulic turbine, the combination with a runner having an inner and outer series of vanes, a partition ring separating l said series one of which has a greater number of vanes than the other, of an intake for the ilow to said runner, stay vanes between said intake and runner, and gate mechanism disposed within said vanes for controlling flow to said runner.

22. ln a hydraulic turbine, the combination with apropeller type runner having an inner and outer series of vanes, a partition ring separating said series, one of which has a greater number of vanes than'the other, of an intake for the iow to said runner, stay vanes between said intake and runner adapted to impart a whirling motion to the turbine low, and gate mechanism operable at partgate to allow ow to only one of said series of vanes.

23. In a hydraulic turbine, the combination with a propeller type runner having an inner and outer series of vanes, a partition ring separating said series one of which has a greater number of vanes than the other, of an intake for the flow to said runner, stay vanes between said intake and runner adapted to impart a whirling motion to the turbine flow,- and gate mechanism operable to allow ow simultaneously to both series of vanes or only to one of said series. 4

2A. In a hydraulic turbine, the combination with a runner having an inner and outer series of vanes, a partition ring separating said series one of which has a greater number of vanes than the other, of an intake for the flow to said runner, stay vanes between said intake and runner adapted to impart a whirling motion to the turbine flow, and gate mechanism operable to allow flow to only the outer series of vanes.

25. In a hydraulic turbine, the combination with a runner having an inner and outer series of vanes, a partition ring separating said series, one of which has a greater number of vanes than the other, of an intake for the ow to said runner, stay vanes between said intake and runner adapted to impart a whirlin motion to the turbine flow, gate mechanism operable to allow flow to only the outer series of vanes, and means for supplying air to the inner series of vanes during said latter operation.

26. In a hydraulic turbine, the combination comprising an intake passage turning from a radial to an axial direction, guide vanes in the radial portion thereof for whirling the iow passing therethrough, and an axial flow runner disposed in the axial portion of said passage, and spaced from said guide vanes to form a transition space there# between, said runner having unshrouded blades with an intermediate partition while the blades oli the inner side of said partition are spaced to form an axial opening therebetween.

27. In a hydraulic turbine, the combination comprising an intake passage turning from a radial to an axial direction, guide vanes in the radial portion thereof for whirling the flow passing therethrough, andan axial flow runner disposed in the axial portion of said passage, 0'uide vanes to form a between, said runner and spaced from said transitlon space therehaving inner and outer 5 series of blades of different number.

charge passage the intake portion thereof rnlng from a radial to an axial direction,

and a runner disposed in said passage and having blades provided with an intermediate partition ring to form inner and outer series of blades, said outer series having a different number of blades than the inner series, and guide vanes adapted to impart whirl to the flow through said intake and being common to both series of blades.

LEWIS FERRY MOODY. 

